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By Andrew Bamber

The introduction of pre-concentration technology into the underground narrow-vein mining scenario has the potential to change the entire economics of utilizing bulk-mining methods in these situations. An idealized integrated underground mining and processing system, comprising elements of bulk mining, underground preconcentration and backfill systems is presented. Through simulation and a systems engineering approach, the implications of enabling the utilization of bulk mining methods in a narrow vein deposit through the adoption of this technology is considered. Parameters considered include orebody characteristics, ore mineralogy, grade, metal value, mining rate and cost.

Oct 1, 2004

By A. Vien, A. J. Neale, B. C. Flintoff, R. P. Edwards

Froth flotation is one of the most widely used and effective processes for mineral beneficiation. First introduced in 1911, flotation technology has seen many developments over the past 80+ years. Innovations in reagent chemistry, equipment design, process analysis and process control have given design and plant engineers a powerful set of "tools" for process optimization. However, it does not follow that all flotation systems are optimized. As Klimpel observes: "The problem with the industrial flotation process is that it is relatively easy to get reasonable results, and relatively difficult to get excellent results" Klimpel (I 988). While reasonable was sufficient in the past, competitive forces will make excellent necessary in the future. Judging by the activities in many Canadian plants this transition is already underway. This paper examines the role of some of the optimization "tools" in effecting this change.

Jan 1, 1994

By T. A. Grammatikopoulos, B. Vasily, A. H. Clark

"The St. Lawrence deposit is a large wollastonite skarn (ca. 9 Mt @ 41.3% wollastonite) adjoining the gabbroic-to-syenitic Leo Lake pluton in the granulite facies Frontenac Terrane of the Grenvillian Central Metasedimentary Belt. It occurs within a horseshoeshaped horizon of quartzite, open to the east. The skarn extends over 1.2 km2, and comprises wollastonite-dominant, wollastonite-clinopyroxene, and diverse quartz-feldspar-sulphide (-titanite) layers, interbanded with, and strongly folded within, the quartzite. As in the world-class wollastonite deposits of the Willsboro district, New York, no carbonate protolith is preserved, and calcite is a negligible constituent of the mineralized zones. Wollastonite development is nonetheless ascribed to metasomatism of a metacarbonate unit by magmatogene, silica-rich, CO2-poor (XCO2 < 0.05) fluids, at P = 350 MPa and ca. 560°C, or, alternatively, 550 MPa and ca. 630°C.Several high-grade zones, averaging >40% but locally exceeding 80%, of translucent, white, tabular wollastonite grains, with lengths of 0.2 cm to 5 cm, have been delimited by drilling. Preliminary beneficiation studies yield high aspect-ratio and high-purity (low Fe and Mn) concentrates.St. Lawrence compares favourably to other known prospects and operating wollastonite deposits: having good chemical and physical properties, low iron content, and high aspect ratios (>20:1). In addition, the deposit has a favourable size and location, and will benefit from a low Canadian dollar. Canada currently has no wollastonite production."

Jan 1, 2003

By Xiang-dong and Zhu, Xia-jie Hao, Yi-lin Fan, Quan Jiang, Lian-xing Hu, Xia-Ting Feng, Shao-jun Li

"Columnar jointed basalt (CJB), which typically originates from lava flows, is characterized by a special geological structure. The joint network inside the CJB is self-organized into a rough hexagonal arrangement. The field test and measurement during the unloading excavation showed that the columnar joint sets and other internal joint sets not only are important for determining the mechanical properties of the CJB, but also induced its asymmetric unloading deformation and failure. A constitutive model, which considered mechanical deterioration of both the joint sets and rock blocks, was also developed to simulate the unloading behaviour of the CJB. The crack-confinement supporting method for surrounding CJB was developed to overcome the failure of columnar jointed rock mass in the diversion tunnel. Application to the CJB segments of the diversion tunnels in the Baihetan project indicated that this supporting method was reasonable and efficient. INTRODUCTIONColumnar jointed basalt (CJB) rock mass, which typically originates from lava flow, is characterized by a special joint structure. The joint network of the CJB is self-organized into a roughly hexagonal arrangement and leaves behind an ordered colonnade. The widely accepted current view regarding the formation of columnar jointing involves a thermally induced contraction–cooling mechanism (Peck and Minakami, 1968; Degraff and Aydin, 1987; Budkewitsch and Robin, 1994; Lore et al., 2000; Goehring et al., 2006). Although the columnar basalt formation mechanism is fairly understood, the geotechnical characteristics of such rock mass are not well established. In practice, joint sets always induce the multi- failure modes of surrounding rock in the tunneling space (Ibarra et al., 1996; Waltham and Swift, 2004; Mahendra and Bhawani, 2008).According to conventional wisdom in rock mechanics, structural joints affect the mechanical response of rock mass by introducing strong anisotropic effects (Barton and Bandis, 1980; Hudson and Priest, 1983; Brady and Brown, 1985). The columnar jointed rock mass should be considered an anisotropic material given that the joint sets are distributed with some principal directions and characteristic spacing distributions (Cundall and Fairhurst, 1987; Hoek et al., 1998; Wu and Wang, 2001; Budetta and Nappi, 2011; Fortsakis et al.,2012). Columnar jointed rock mass would result in structurally controlled failure patterns, even serious disasters during underground excavation because of the low shear and tensile strengths of intensely joints (Gencer,1985 ;Ishida and Uchita, 2000; Jia and Tang, 2008). The CJB rock mass in the Baihetan hydropower station has exhibited serious stability issues, including sliding, fracturing and even collapse (Shi et al.,2008). Therefore, the geotechnical and geomechanical characteristics of such rock mass should be assessed through in situ investigation and numerical analysis to minimize future accidents during underground unloading excavation."

Jan 1, 2015

By C. J. Coulson, G. A. McKay, A. M. Cormie

"The Leitch mine, in the Beardmore area, Thunder Bay district, Ontario, is a part of the Leitch estate. It includes a group of patented claims, staked by P. A. Leitch of Port Arthur early in the century, along bands of jasper, hematite, iron-bearing slates, carbonatized schists, and greywacke, commonly known as 'iron formation'. The folding and shearing in these variably interstratified beds is a striking structural feature. The vein pattern is very definitely related to these structures.ROCKSThe rocks in the area are typical Keewatin lavas-greenstone-overlain by a series of Timiskaming sediments consisting of arkosic greywacke, iron formation, slate, greywacke, conglomerate, and greywacke, in this order from the contact. The sedimentary beds are generally conformable with the older rock contact except on local folds.Small intrusions of diorite occur as nearly vertical dykes and are believed to be of Algoman age. To the northwest of the mine there are larger intrusions of granodiorite belonging to the same period.Several dykes of quartz diabase up to 100 feet in width, striking generally north and south, with a vertical dip, cross the property. These have been classified by W. C. Laird as pre-Keweenawan in age. One of these dykes in particular is of importance for it cuts through the No. 2 vein and serves as a pillar when stoping. It is approximately 6 feet wide.The youngest rock type represented is a sheet of olivine diabase that extends over an area of thousands of square miles in and around lake Nipigon. It underlies most of this area and its outcrops form some of the most interesting topographical features, with fault scarps rising hundreds of feet. In the vicinity of the mine shaft the sheet is about 600 feet thick and extends from a depth of 1,871 feet to approximately 2,470 feet. It has a dense, hard, chilled margin and a sharp, tight contact. It intruded the sediments with very little lateral disturbance. The chief effect was baking, which darkened and hardened the greywacke near the contact. The sheet dips flatly to the cast."

Jan 1, 1954

By L. H. Michaud

"Albian Sands Energy (ASE), an oil sands surface mining and extraction operation, is currently undergoing start-up and is scheduled to ramp-up to full production by mid-2003. Startup includes the selection and implementation of over 75 IT systems or computer applications which include: engineering applications; systems required to control mining activities, maintenance, the processing plant and utilities; and also systems required to run the company, such as human resources, finances and inventory/ warehousing.This paper outlines the processes used for the selection, implementation and integration of these systems in order to optimize the use of information and to meet the technical, business and IT requirements of the company. The first step in ASE’s approach to identifying system requirements is the development of a business activity model, outlining all tasks involved in running the operations. The computer applications required to accomplish each task are then identified by having the IT team work closely with each technical and business unit. Historically, at some companies, the selection of systems has been led by the IT team or by consultants, with little input from the technical or business units. Typically, this results in products that do not meet the company’s expectations. To ensure a more positive outcome, ASE believes that it is imperative that the company’s technical and business people be closely involved in the selection process.Integration of the IT systems is also key, including linking all applications through a data warehouse and EDMS. Over 120 required integrations have been identified. This ensures the storage of all data in only one location, data security, and easy data and document retrieval for all requirements throughout the company"

Jan 1, 2003

By Mahmoud Shakeri1

Various types of thin-walled structures have been frequently used as energy absorbers to mitigate the adverse effects of impact and hence protect the vehicle structure under consideration when subjected to different loading conditions. Compression tubular structures that buckle in a progressive manner, can be used to advantage, providing inexpensive and versatile, but nevertheless weight and stroke efficient energy absorbers. In this paper quasi-static nonlinear finite element simulations are performed to study the effects of number of corners of the cross-section, wall thickness, plastic hardening rate of material, foam-filler and load angle on deformation mode and mean crushing force of tube. Crush strength increases as the number of corners of the cross-section increases, though it almost saturates for the number of corners beyond 11. Higher plastic hardening rate stabilizes the collapse pattern. Foam-filled tubes seem to have higher critical load angles in oblique loading and display a more stable and gradual decrease in mean load over the transition region. Substantial decrease in the initial peak load and dynamic load at any a given deflection was observed as the load angle increases. The investigation of bitubal arrangements and Multi-cell tubes reveals that these may be preferable to monotubal specimens due to the presence of the inner profiles. In addition, a comparison is conducted between the numerical and experimental results of the mean forces of some special angle elements. Good agreement is obtained.

Oct 1, 2011

By L. Su, S. Liu, K. Jiang, K. Xie

The reduction of iron dissolution and acid consumption is fairly important in the extraction of Ni and Co from laterite ores from both economic and efficiency perspectives. BGRIMM conducted detailed research to investigate the behavior of iron in a nickel laterite leaching process. The mineralogy of Ni and Co was studied. In limonite ore about 76% of nickel is present in goethite while in saprolite ore 79% of nickel is associated with magnesium and silicon minerals. Test work revealed that limonite can be decomposed completely with enough acid concentration during atmospheric leaching. More than 98% of Ni and Co were leached into solution while 85% of the iron was also dissolved with 130-140 g/L iron in solution. Iron precipitates as hematite in the temperature range 250-270?C without neutralization reagents. That’s why limonite is treated by high pressure acid leaching (HPAL) technology to achieve nickel extraction and iron precipitation in the same autoclave. BGRIMM’s test results indicated that the remaining acid in atmospheric leaching solution and acid released by iron precipitation at a lower temperature was enough to leach saprolite efficiently. The so-called inverse leaching technology leaches limonite at atmospheric condition and the leaching slurry combined with saprolite is pumped into an autoclave to leach saprolite at 150-170?C. In the autoclave iron precipitates as hematite without acid consumption. Total nickel and cobalt extractions in the test program were more than 90% with iron content in solution below 8 g/L. In this inverse process iron dissolves in the atmospheric leaching stage and precipitates as hematite in the low temperature leaching stage. Compared with HPAL the leaching temperature is reduced to 150-170 ºC from 250-270 ºC. Compared to atmospheric tank leaching acid consumption is reduced from 850-950 kg/t ore (atmospheric) to 550-650 kg/t ore (inverse).

Jan 1, 2016

By Michel Aubertin

Les digues de retenue de résidus miniers devraient être conçues de façon à supporter les charges les plus défavorables qui puissent être anticipées. Les nombreux incidents survenus au cours des dernières années à travers le monde montrent toutefois que la stabilité de ces ouvrages reste encore problématique. Les cas de rupture les plus courants sont reliés aux glissements le long des pentes, à la liquéfaction des rejets, au débordement des bassins, ainsi qu?à l&apos;érosion régressive et de surface. Après avoir rappelé la nature et l?importance des certains incidents récents, l?origine de ces problèmes est brièvement présentée. On aborde ensuite le lien entre les critères à adopter pour la conception des ouvrages et les risques associés à leur rupture. De nouvelles avenues pour aider à contrôler certains problèmes sont enfin discutées, en mettant l?emphase sur la codisposition des roches stériles dans le parc à résidus miniers.

Nov 1, 2002

By J. H. Douglas, A. F. Matheson

"The Hard Rock is the most easterly producing mine in the Little Long Lac area. The Company was formed in 1934 to develop a surface showing of gold in quartz made by a prospector, W. W. Smith, in 1931. Although some ore was eventually produced from this discovery, the principal orebody, hidden below 10 feet of muskeg, was found about 1,000 feet to the north by exploratory diamond drilling early in 1938 from the No. 2 shaft workings at the 250-foot level.Production started in 1938 and to January 1, 1947, 201,000 oz. gold had been obtained from 1,165,282 tons of ore mined and 869,397 tons milled. Of this ore about 15 per cent came from the development and mining of the original orebodies discovered at the surface. The remainder came from the ore found by the underground diamond drilling done in 1938. Of the latter ore, the Company estimated, at January 1st, 1947, only 140,000 tons remained. The orebody, therefore, contained approximately 1,100,000 tons.OREBODIES AND GENERAL GEOLOGYThe orebodies of the Hard Rock mine are of two main types: the quartz ore of the south and No. 1 shaft zones, and the sulphide ore of the north zone. The quartz ore consists of white quartz veins mineralized with sparse, fine, light-coloured pyrite, or, less commonly, nests of coarse, crystalline, light pyrite. A little tourmaline, scheelite, pyrrhotite, chalcopyrite, arsenopyrite, and native gold are also present. Native gold occurs in a few places in quartz veins in exceedingly rich cemcentrations, apparently where there are large, light-coloured, pyrite crystals of imperfect form. The ore of the north zone is massive pyrite with arsenopyrite and in places pyrrhotite. Many short irregular quartz veins, from a few inches to 2 feet in width, are also present, but the quartz forms a very small percentage of the whole. The veins may be flat to vertical, and sulphides on one or both sides replace the host rocks. The gold is closely associated with the sulphides . The quartz is commonly barren except where it contains sulphides or along the borders of the sulphide ore zone where native gold is not uncommon in quartz stringers."

Jan 1, 1954

By L. E. Gutiérrez

A new filtration model based on porous media transport theory is presented. It predicts capacity and final moisture content in the filtered cake as a function of design and operational variables at the plant. FilterSim® is the computer code where this new model is programmed. Application of FilterSim® to ten-month operation of an industrial copper concentrate filtration plant is shown on a daily basis and using a single set of internal parameters for the whole period. Average error is less than 5%, both in capacity and moisture estimation. FilterSim® abilities to optimize industrial filtration plants as well as to estimate future budgets are illustrated with several real examples.

Jan 1, 2007

By C. Karpuz, Y. S. Istanbulluoglu

This paper describes the results of convergence measurements conducted about five years for the re-use gate roadways at OAL lignite mine in Turkey. Double lignite seams separated with a marn layer, are mined with long-wall retreating mining system at the mine. Rib pillar has been abandoned and gate roadways were planned to be packed for the re-use of full extraction. Various packing systems have been attempted, namely three rows of woodenchock, one row of wooden chock plus concrete wall and concrete wall only. The re-use of maingate roadways packed with wooden chock yielded 62% of closure. Lastly developed concrete packing of 3 meters wide and specially developed support set composed of three friction props and a cap, which is a modification of yieldable set, have successfully maintained the main and tail gate roadways stability with a total vertical convergence of 32%. Good correlation has been established between pack stiffness and floor heave as well as maingate and tailgate convergences. The elimination of rib pillars by re-use of gate roadways increased the coal recovery by 20% and decreased the development/production ratio from 0.065 m3/ton to0.022 m3/ton.

Jan 1, 1997

By Ch. Wenzl

Anodes must have a certain physical and chemical quality in order to provide uniform anodic corrosion and meet the requirements of electrorefining, i.e. to achieve a high current efficiency, low energy consumption, low amount of anode scrap and low effort together with high cathode quality. Various properties of the anodes can be influenced directly by the casting process, which is the interface of pyro- and hydrometallurgy of copper. The aims of anode casting ? high output and long mould lifetimes ? are not consistent with good physical anode quality. The physical requirements of an anode are smooth surfaces, uniform weight and thickness, minimal edge effects, minimal distortion of the body and the lugs, as well as a homogeneous microstructure, in order to achieve uniform dissolution behaviour. The chemical quality of the anode copper is a task of electrorefining operations, but the elemental distribution within the anodes, which should be as homogeneous as possible in order to provide uniform anodic corrosion, can be influenced by the casting process.

Jan 1, 2007

By L. V. Volkov

The equilibrium of the CuO-Cu20-Cu+-Cu2+ system with various chloride ion concentrations in solution in the presence or absence of an oxidant was investigated. It is shown, that, regardless of the presence or absence of chloride ions or oxidant (oxygen) in the system, the process can be divided into three stages, which are characterized by differing rates and mechanisms of metallic copper cementation and cuprite precipitation and, hence, lead to differing rates of the dissolution of nickel into solution. The effect of the concentrations of chloride ion and oxidant on the phases in the process residues is also discussed. The addition of an oxidant increases the amount of cuprite (Cu20) in the leach residue. With increasing chloride ion concentrations, the rate of copper cementation increases, even without an oxidant in solution. The results of these laboratory experiments and the mechanisms developed are consistent with analysis of samples of industrial cement copper obtained from the Severonickel Combine.

Jan 1, 2007

By A. Probst, J. A. Finch

"Solids concentration (weight % solids) profiles and the clear liquid/slurry interface level (mud-line) were determined from conductivity measurements in thickeners at Falconbridge&apos;s Strathcona mill (Ni concentrate and non-mag thickeners) and Kidd Creek Division (Cu, Zn concentrates and final tails in the concentrator and a jarosite thickener in the Zn plant).The conductivity measurement system consisted of a probe 1.5 m in length with 23 electrode cells, a 24-channel relay, a conductivity meter and a computer. A conductivity profile is collected which locates the mud-line by a sharp change in conductivity. The conductivity measurements are readily converted to solids concentration profiles using a model due to Maxwell.The results from conductivity measurements were compared with direct measurements on local samples obtained using a modified Noranda sampler.It is concluded that the conductivity technique is applicable to locate the mud-line and to estimate the solids concentration profiles in thickeners. This on-line informnation could improve the operational efficiency of industrial thickeners."

Jan 1, 1994

By Denghong Wang

Abstract- The Ashele Cu-Zn deposit is a recently discovered volcanogenic massive sulfide deposit in Xinjiang, China, hosted by Lower to Middle Devonian submarine bimodal volcanic rocks. The primary ores of this polygenetic deposit are represented by massive syn-depositional pyrite, chalcopyrite, and sphalerite, and were formed by submarine exhalation. Hydrothermal alteration consists of strong sericitization, chloritization, silicification, and carbonatization of the metavolcanic rocks beneath the massive orebodies. Depletion of Na2O is an obvious chemical change in the hydrothermal halo. Geological and geochemical evidence suggest that the Ashele Cu-Zn massive sulfide deposit was formed by submarine exhalation related to bimodal volcanic rocks, trapped in a rifting basin, then deformed by shearing, and thermally metamorphosed by the intrusion of dacitic porphyry. Sulfur and lead isotopic studies indicate that metals such as copper and zinc may have originated from spilites, but that volatile components, especially sulfur, were derived directly from submarine volcanic magmas.

Jan 1, 1999

By H. K. Olsen, B. Thomassen, H. K. Schønwandt, L. Grahl-Madsen, H. Stendal

Abstract-The central part of the early Proterozoic Ketilidian orogen in South Greenland consists of an I-type granitoid batholith transected by four regional NE-SW-trending shear zones. The batholith was probably emplaced during subduction, from the south toward the Archaean craton in the north, in a sinistral transpressional system. A regional sediment sampling program covering 5000 km2 shows a close connection between a gold-mineralized trend and one of the major shear zones within the epizonal facies of the batholith. The gold mineralization is not directly related to the major shear zones, but occurs in quartz-veined and silicified second-order structures. High-grade (up to 114 ppm Au over 6 m) low-tonnage mineralization is found within these second-order structures cutting both amphibolites and granitoids. The mineralization is characterized by negligible or small alteration halos. Gold is associated with various element combinations of enhanced As-Bi-W- Cu, which indicate that the mineralization is mesothermal in origin.

Jan 1, 1995

By T. A. Grammatikopoulos, B. Vasily, A. H. Clark

"The St. Lawrence deposit is a large wollastonite skarn (ca. 9 Mt @ 41.3% wollastonite) adjoining the gabbroic-to-syenitic Leo Lake pluton in the granulite facies Frontenac Terrane of the Grenvillian Central Metasedimentary Belt. It occurs within a horseshoeshaped horizon of quartzite, open to the east. The skarn extends over 1.2 km2, and comprises wollastonite-dominant, wollastonite-clinopyroxene, and diverse quartz-feldspar-sulphide (-titanite) layers, interbanded with, and strongly folded within, the quartzite. As in the world-class wollastonite deposits of the Willsboro district, New York, no carbonate protolith is preserved, and calcite is a negligible constituent of the mineralized zones. Wollastonite development is nonetheless ascribed to metasomatism of a metacarbonate unit by magmatogene, silica-rich, CO2-poor (XCO2 < 0.05) fluids, at P = 350 MPa and ca. 560°C, or, alternatively, 550 MPa and ca. 630°C.Several high-grade zones, averaging >40% but locally exceeding 80%, of translucent, white, tabular wollastonite grains, with lengths of 0.2 cm to 5 cm, have been delimited by drilling. Preliminary beneficiation studies yield high aspect-ratio and high-purity (low Fe and Mn) concentrates.St. Lawrence compares favourably to other known prospects and operating wollastonite deposits: having good chemical and physical properties, low iron content, and high aspect ratios (>20:1). In addition, the deposit has a favourable size and location, and will benefit from a low Canadian dollar. Canada currently has no wollastonite production."

Jan 1, 2003

By Lopatka. M. J.

This paper presents the results of 3 tons skid steer 6x6 wheel robot drive system field tests. The aim of the investigation was verification of assumed data for drivetrain diesain and forces identification in the drivetrain system during maneuvering and crossing obstacles. Robot has hydraulics drive system with motors in the wheels and hydraulic suspension system. The neded drive torque on wheels was determined by pressure measurnig on motors.

Aug 1, 2013

By P. J. Deveaux, M. J. Kreczmer

The Tartan Lake deposit 12 km northeast of Flin Flon, Manitoba, was discovered in March of 1984 during the investigation of a VLF anomaly. The discovery hole intersected 16.83 metres averaging 21 gm Au/tonne. Since then, 99 holes, over 21,000 metres, have been drilled outlining 419,491 tonnes grading 11.79 gm Au/tonne in a di stinct group of mineralized lenses referred to as the Main Zone. Three other mineralized zones are known on the property but no reserves have been allowed for these, the South , East and Base Line zones. The Main Zone consists of seven parallel, east-west striking, quartz lenses. The lenses dip steeply to the north and plunge steeply west to northwest. Lens number l strikes for 160m and extends vertically to the 90m level. Within th is lens there is a 60m interval of low grade materi al. Lens number 2 is located about 5-l0m within the foo twall of Lens number I. Near surface this lens stri kes for 40m, at 200m level the strike length increases to 200 m. To date the deepest mineralization on Lens 2 has been intersected at a vert ical depth of 527m. Five smaller lenses are located in the foo twall of Lens 2 , containing gold va lues similar to the two main lenses but erratically distributed. The South Zone, located 100m south of the Main Zone, strikes east-west fo r l00m above the 100m level. The East Zone, found 230m east of the Main Zone, strikes fo r 80m and may possibly be an ex tension of the South Zone. The Base Line Zone is located 275m south of the Main Zone. Sporadic, but very significant gold intersections have been obta ined1n all three zones. Gold-bearing quartz-ca rbonate tourmaline veins are generally confined to a silicous crystal tu ff hori zon. The crystal tuff exhi bits fi ve distinct types of alteration: silicification, sericitization, ca rbonati zation, chlorit ization and pyritization. Silicification has resulted in a perasive addition of silica and the generation of multiple quartz veins. Sericiti zation is restricted to the crystal tuff. All rock units are pervasively carbonatized . Ankerite is abundant in the quartz veins and within the shear zones, particul arly those located along the chilled margin of a nearby gabbro-diorite intrusion. Chloritization is widely spread th roughout the rock units, while pyritization fo rms a broad alteration halo associated with the orebody. Sulphide accesso ry minerals associated with the gold , whi ch fo r the most part appears to be free, are chalcopyrite and pyrite. Generally, the higher grade gold values are related to an increased content of sulphides in the qua rtz veins. The average sulphide content in the deposit is less than 5 %.

Jan 1, 1986